Preparation of lime nitrogen.



GB monrnu Aneus'r s'rrntrasau, or NIAGARA FALLS CENTRE, ou'ran'ro,CANADA.

PREPJ KRATION OF LIME NITROGEN.

NdDrawing.

.To all whom it may concern:

Be it known that I, Jon Monrnn AUGUST STILLESEN, a subject of the Kingof Norway, residing at Niagara Falls Centre, in the Province of ()ntarioand Dominion of Can- ,ada, have invented certain new and usefulimprovements'in Preparation of Lime Nitrogen, of which the following isa full, clear, and exact specification. i

This invention relates to preparation of lime nitrogen, and. moreparticularly has reference to improvements whereby a more neutralproduct may'be obtained than has heretofore been known.

It has been proposed to form nitrogen compounds by passing nitrogenthrough heated calcium carbid which commonly eonalkaline.

tains free lime (CaU), sometimes as much as 1.5%, and the resulting limenitrogen will contain this free lnne as an im 'aurity. For

use in fertilizers, the free limemay be 'objeetionable and has a badeffect on some soils, since the compound is too strongly I havediscovered that this ob- ]:ection can be remedied by treating the limecontaining material with carbon dioxid at a temperature such as'to causethe lime to the more neutral ear-' cinm car-bid has been treated withnitrogen,

with or Without a flux, according to the typical reaction.

eac -2n: CaNCN+C the fluxes, if used, being unchanged, but

promoting the reaction. and rendering the product non-hygroseoplc.iVhatever lnne the carbid contains, which is usually about 15% is unchaned b 1. the treatment with nitrogen, and according tothis invention, I

propose to treat such carbid, or the resultant lime nitrogen containinglime, with carbondioxid, at a temperature less than the combi-' nationof' carbon and oxygen, whereby the strongly alkaline lime (CaO)' willbe, in

whole or in part, converted tothe more nearly neutral carbonate CaCO)and thereby remedy the objection heretofore present in the alkalineproduct. The reaction between carbid and nitrogen takes place at about1000 (3., and I have discovered that,

Specification of Letterslatent;

Application filed May 1, 1909. Serial No. 493,261.

' mama-tan. 24, 1911.

after the nitrogen reaction is completed and the product cooled to below100 0., the lime can be changed to the more neutral carbonate byadmitting a sufficient quantity of carbon dioxid gas to the furnace inintimate relation therewith. This takes place accordingto the reaction Ioao ooFcaco Also, the carbid containing lime may b first similarlytreated, at the proper temperature, and then. with nitrogen at thepropertemperature, to secure lihienitrogen,

this being Within the scope of my invention.

If any lime should be formed in the nitrogen furnace by decomposition oftheczirbid, it could be neutralized by subsequent treatment, orneglected.

If a flux be used to promote the combination with nitrogen and obtain agreater yield such'as a mixture of calclum fluorid and cryolite, thereaction might be exemplified by the equation P This product can then.be treated first with carbon'dioxid at about 100 C. to remove the withor without a flux, or with or Without free carbon. Preferably, I firstproduce lime nitrogen from carbid and nitrogen with the-assistance of aflux and heat, eliminate the free carbon therefrom by oxidation, andthen neutralize the free lime; .by further treatment with carbon dioxidlower temperature. Thereby a new product is obtained comprising limenitrogen and lime carbonate, containing a larger percentageof combinednitrogen than has heretofore been obtained and less alkaline inreaction, depending upon the proportion of free carbon eliminated andthey proportion of lime neutralized,

The process can be carried out in any suitable furiiace havingprovisionifor heating, supplying and controlling the materials employed;The'materials used will be obtained in any suitable mannerrlot necessaryto be specifically described herein, and of course the proportions ofmaterials may be varied 'bonate with free lime.

1 temperature in the .without departing from the scope of the bonatefrom the alkalineportion by treatment with carbon dioxid.

2. The process of neutralizing lime in lime nitrogen .inanufactureconsisting in converting the lime to carbonate by treatment with carbond'ioxi'd.

3. The process of neutralizing uncombined lime in lime nitrogenconsisting in treating the lime nitrogen with carbon dioxid at atemperature that will form calcium car- 4. The process of preparing limenitrogen consisting in treating carbid of calcium with nitrogen at anelevated temperature, and then with carbon dioxid at a temperature suchas to form calcium carbonate with tree lime. v

54A process of preparing lime nitrogen consisting in treating carbid ofcalcium with nitrogen at an elevated temperature, eliminating freecarbon therefrom, and then neutralizing the free lime.

6. The process of preparing lime nitrogen consisting in treating carbidof calcium containing lime with nitrogen at an elevated presence of aflux, and then neutralizing the lime by treatment with carbon dioxid. y

7 The process of preparing lime nitrogen consisting in treating carbidof calcium containing lime with nitrogen at an elevated temperature inthe presence of a flux, and then treating said product with carbondioxid at:a'tempera ture such as to convert the lime to carbonate. I

8. The process of preparing lime nitrogci'i consisting 1n treatingcarbid'of calcium with nitrogen at an elevated temperature, then whileat approximately the same temperature with carbon dioxid, and then at alower temperature with additional carbon dioxid.

9. The process of preparing lime nitrogen consisting in treating carbidof calcium with nitrogen at anelevated temperature, and then at atemperature below that of formation of carbon moi'ioxid with carbondioxid.

10. A process of preparing lime nitrogen consisting in treating carbidof calcium with nitrogen at an elevated temperature, then with carbondioxidat a lower temperature so as to convert free lime into carbonateof lime.

11. A process of preparing lime nitrogen consisting in treating carbidof calcium with nitrogen at anelevated temperature in the presence of aflux, then treating said product with carbon dioxid at'a lowertemperature so as to convert free lime into carbonatef'of lime. t

12. A process of preparing lime nitrogen consisting in treating carhidof calcium with nitrogen at an elevated temperature in the presence of aflux comprising calcium fiuorid,

then treating said product with carbon dioxid at a lowerv temperature soas to convert free lime into carbonate of lime.

13. A composition of matter comprising calcium cyanamid, calciumcarbonate, and a flux comprising a fiuorin compound.

In testimony whereof I aifix' mysignature,

in presence of two witnesses. g I JOB MORTEN AUGUSTSTILLESEN.

\Vitnesses: i

HARRY MARSEY, E. MAYNARDWVHEELE;

